2A551 Practice Test Volume 2

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  • 1/100 Questions

    The type of jack normally used to change a tire on the aircraft is the

    • Axle
    • Tail
    • Nose
    • Fixed-height
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About This Quiz

The 2A551 Practice Test Volume 2 assesses knowledge crucial for aircraft maintenance, covering equipment like maintenance stands and jacks, and understanding of systems including hydraulic and nitrogen servicing units. It's designed for professionals aiming to enhance their technical skills in aircraft upkeep.

Aircraft Maintenance Quizzes & Trivia

Quiz Preview

  • 2. 

    Matter is any substance that has volume and

    • Can be seen

    • Occupies space

    • Has constant volume

    • Cannot be compressed

    Correct Answer
    A. Occupies space
    Explanation
    The correct answer is "occupies space" because matter refers to any substance that has volume, meaning it takes up space. This implies that matter occupies space in the physical world. The other options provided, such as "can be seen," "has constant volume," and "cannot be compressed," are not accurate definitions of matter and do not encompass the essential characteristic of matter, which is its ability to occupy space.

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  • 3. 

    The most common type of material used for fuselage construction

    • Steel

    • Titanium

    • Magnesium

    • Aluminum alloy

    Correct Answer
    A. Aluminum alloy
    Explanation
    Aluminum alloy is the most common type of material used for fuselage construction due to its favorable properties. It is lightweight, yet strong and durable, making it ideal for aircraft structures. Aluminum alloys also have excellent corrosion resistance, which is crucial for withstanding the harsh conditions of flight. Additionally, aluminum is readily available and relatively inexpensive compared to other materials like titanium or magnesium. Therefore, it is the preferred choice for constructing aircraft fuselages.

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  • 4. 

    The axis that extends lengthwise through the fuselage from the nose to the tail is the

    • Lateral

    • Vertical

    • Horizontal

    • Longitudinal

    Correct Answer
    A. Longitudinal
    Explanation
    The correct answer is longitudinal. The question is asking about the axis that runs from the nose to the tail of the fuselage. The term "longitudinal" refers to a lengthwise direction or axis, which aligns with the description given in the question. The other options - lateral, vertical, and horizontal - do not accurately describe an axis that extends from the nose to the tail.

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  • 5. 

    Aircraft have trim systems to

    • Reduce the amout of lift

    • Prevent the aircraft from stalling

    • Correct minor deviations in flight altitude

    • improve augmented lateral control surface movement

    Correct Answer
    A. Correct minor deviations in flight altitude
    Explanation
    Aircraft have trim systems to correct minor deviations in flight altitude. These systems allow pilots to adjust the position of control surfaces, such as elevators or stabilizers, to maintain a desired altitude without having to constantly apply manual pressure on the controls. By making small adjustments to the trim, pilots can ensure that the aircraft remains level and at the desired altitude, improving flight stability and reducing the workload on the pilot.

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  • 6. 

    The most outstanding characteristic of a liquid is its

    • Rigidity

    • Usability

    • Ability to compress with in its container

    • Ability to conform to the shape of its container

    Correct Answer
    A. Ability to conform to the shape of its container
    Explanation
    The correct answer is "ability to conform to the shape of its container". Unlike solids, liquids do not have a fixed shape and can take the shape of their container. This is due to the weak intermolecular forces between liquid particles, allowing them to flow and move freely. Liquids also have the ability to fill the entire volume of their container, making them adaptable to different shapes and sizes.

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  • 7. 

    If 50 PSI of cylinder pressure acts on a 5 square-inch piston head, the resulting force will be

    • 150 lbs

    • 200 lbs

    • 250 lbs

    • 300 lbs

    Correct Answer
    A. 250 lbs
    Explanation
    The resulting force can be calculated using the formula: force = pressure * area. In this case, the pressure is 50 PSI and the area is 5 square inches. Multiplying these values together gives us a resulting force of 250 lbs.

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  • 8. 

    When an 8 square-inch piston moves 5 inches within a cylinder, the volume of liquid displaced will be

    • 4 cubic inches

    • 40 cubic inches

    • 400 cubic inches

    • 4000 cubic inches

    Correct Answer
    A. 40 cubic inches
    Explanation
    The volume of liquid displaced can be calculated by multiplying the area of the piston by the distance it moves. In this case, the area of the piston is 8 square inches and it moves 5 inches. Therefore, the volume of liquid displaced is 8 square inches multiplied by 5 inches, which equals 40 cubic inches.

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  • 9. 

    Atoms are made up of

    • Molecules, protons and neutrons

    • Protons, molecules, and electrons

    • Molecules, neutrons and electrons

    • Protons, neutrons and electrons

    Correct Answer
    A. Protons, neutrons and electrons
    Explanation
    Atoms are the basic units of matter, and they are made up of three subatomic particles: protons, neutrons, and electrons. Protons have a positive charge, neutrons have no charge, and electrons have a negative charge. Protons and neutrons are located in the nucleus of the atom, while electrons orbit around the nucleus in energy levels or shells. This arrangement of protons, neutrons, and electrons determines the properties and behavior of different elements. Therefore, the correct answer is protons, neutrons, and electrons.

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  • 10. 

    Current that periodically reverses is called

    • Potential

    • Reversing

    • Alternating

    • Directional

    Correct Answer
    A. Alternating
    Explanation
    The term "alternating" refers to something that changes or reverses periodically. In the context of current, alternating current (AC) is a type of electrical current that periodically changes direction. This is in contrast to direct current (DC), which flows in only one direction. Therefore, the correct answer is "alternating" because it accurately describes a current that periodically reverses.

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  • 11. 

    Of the following, the maintenance stand that is a scissor-type is the

    • B-1

    • B-2

    • B-4

    • C-1

    Correct Answer
    A. B-4
    Explanation
    The correct answer is B-4. This is because a scissor-type maintenance stand is typically used for larger aircraft, such as commercial airplanes or military cargo planes. The B-4 is a larger aircraft model compared to the other options listed (B-1, B-2, C-1), making it more likely to require a scissor-type maintenance stand for maintenance and repair tasks.

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  • 12. 

    The purpose of a hydraulic system check valve is to

    • All flow only in one direction

    • Prevent loss of fluid if a line breaks

    • Supply on demand pressure to components

    • Relieve excess pressure due to thermal expansion

    Correct Answer
    A. All flow only in one direction
    Explanation
    A hydraulic system check valve is designed to allow flow in only one direction. This is important because it ensures that fluid can flow freely in the desired direction, preventing any backflow or reverse flow. By allowing flow in only one direction, the check valve helps to maintain the proper functioning and efficiency of the hydraulic system. It also helps to prevent any potential damage or malfunction that could occur if fluid were to flow in the wrong direction. Therefore, the purpose of a hydraulic system check valve is to ensure that flow is restricted to only one direction.

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  • 13. 

    The component designed to convert 115/220 volt AC current into 28 volt (or less) DC current to operate the aircraft DC system is the

    • Integrated drive generator (IDG)

    • Frequency and load controller

    • Generator control unit (GCU)

    • Transformer-rectifier (T-R)

    Correct Answer
    A. Transformer-rectifier (T-R)
    Explanation
    The component designed to convert 115/220 volt AC current into 28 volt (or less) DC current to operate the aircraft DC system is the transformer-rectifier (T-R). A transformer is used to step down the voltage from 115/220 volts to a lower voltage, and a rectifier is used to convert the AC current into DC current. This is necessary because the aircraft DC system operates on DC power, and the T-R performs the necessary conversion to provide the correct voltage and type of current for the system.

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  • 14. 

    A Class I MB-2 tractor weighs

    • 2700 lbs

    • 40000 lbs

    • 53000 lbs

    • 500000 lbs

    Correct Answer
    A. 40000 lbs
    Explanation
    The correct answer is 40000 lbs. This is because the question asks for the weight of a Class I MB-2 tractor, and out of the given options, 40000 lbs is the only weight that corresponds to the tractor.

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  • 15. 

    A cracked radome could cause

    • Antenna oscillation

    • Dielectric increase

    • Microwave distortion

    • Electron- deterioration

    Correct Answer
    A. Microwave distortion
    Explanation
    A cracked radome, which is the protective cover for an antenna, can cause microwave distortion. This is because the crack can disrupt the smooth flow of microwave signals, leading to interference and distortion in the transmitted or received signals. The crack may cause reflections, scattering, or diffraction of the microwaves, resulting in a distorted signal.

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  • 16. 

    The type of bearings used on aircraft wheels is

    • Flat roller

    • Straight ball

    • Recessed cone

    • Tapered roller

    Correct Answer
    A. Tapered roller
    Explanation
    Tapered roller bearings are the type of bearings used on aircraft wheels. These bearings are designed to handle both radial and axial loads by having a tapered inner and outer raceway. This design allows for better distribution of the load, reducing friction and increasing the bearing's durability. Tapered roller bearings are commonly used in applications where high radial and axial loads are present, making them suitable for aircraft wheels that experience varying loads during takeoff, landing, and taxiing.

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  • 17. 

    For tires 24 inches or greater outside diameter, the tire shall be removed when the wear reaches the bottom of an tread grove for a continous length of

    • 4 inches

    • 6 inches

    • 12 inches

    • 16 inches

    Correct Answer
    A. 12 inches
    Explanation
    The correct answer is 12 inches because for tires with a diameter of 24 inches or greater, they should be removed when the wear reaches the bottom of a tread groove for a continuous length of 12 inches. This means that if the wear on the tire reaches the bottom of a groove for a length of 12 inches or more, it is considered unsafe and should be replaced.

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  • 18. 

    The greater the current flow through and electromagnet, the

    • Less the strength

    • Greater the strength

    • Greater the retentivity

    • High the reluctance of the core

    Correct Answer
    A. Greater the strength
    Explanation
    The greater the current flow through an electromagnet, the greater the strength. This is because the strength of an electromagnet is directly proportional to the current flowing through it. As the current increases, the magnetic field produced by the electromagnet becomes stronger, resulting in a greater overall strength.

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  • 19. 

    The amount of fluid the MJ-2A reservoir holds is

    • 19 g

    • 27 g

    • 30 g

    • 60 g

    Correct Answer
    A. 27 g
    Explanation
    Based on the given options, the correct answer is 27 g. This means that the MJ-2A reservoir can hold a volume of 27 grams of fluid.

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  • 20. 

    When any force causes a solid to change permanently, the solid is said to have

    • Passed the elastic limit

    • Lost the ability to expand

    • Failed to meet the elastic limit

    • Passed the compression limit

    Correct Answer
    A. Passed the elastic limit
    Explanation
    When a force is applied to a solid and it causes a permanent change in the shape or size of the solid, it means that the solid has passed its elastic limit. The elastic limit is the maximum stress or force that a material can withstand without undergoing permanent deformation. Once the elastic limit is surpassed, the solid loses its ability to return to its original shape and size after the force is removed. Therefore, the correct answer is "passed the elastic limit".

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  • 21. 

    When referring to hydraulic hand pumps, double action means

    • Fluid flow is created with each stroke of the pump handle

    • Fluid flow is created with every other stroke of the pump handle

    • Double volume is displaced with each stroke of the pump handle

    • Double volume is displaced with every other stroke of the pump handle

    Correct Answer
    A. Fluid flow is created with each stroke of the pump handle
    Explanation
    In hydraulic hand pumps, the term "double action" means that fluid flow is created with each stroke of the pump handle. This means that with every movement of the handle, fluid is being pumped and flowing through the system. This is in contrast to "single action" pumps, where fluid flow is created with every other stroke of the pump handle. With a double action pump, the flow of fluid is continuous and consistent with each stroke, allowing for more efficient and effective operation.

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  • 22. 

    Allowing normal operating speed of a hydraulic actuator in one direction while limiting speed in the other direction is done by the

    • Automatic check valve

    • Restrictor check valve

    • Bypass valve

    • Relief valve

    Correct Answer
    A. Restrictor check valve
    Explanation
    A restrictor check valve is used to allow normal operating speed of a hydraulic actuator in one direction while limiting speed in the other direction. This valve restricts the flow of hydraulic fluid in one direction, slowing down the actuator's movement, while allowing free flow in the other direction for normal speed. It ensures controlled and safe operation of the actuator by preventing excessive speed and potential damage.

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  • 23. 

    The purpose of aircraft brakes is to

    • Reduce take off roll

    • Reduce wheel skidding

    • Retard motion using rotation

    • Retard motion using friction

    Correct Answer
    A. Retard motion using friction
    Explanation
    Aircraft brakes are designed to retard or slow down the motion of the aircraft by utilizing the principle of friction. When the brakes are applied, friction is created between the brake pads and the rotating wheels, which generates a force that opposes the motion of the aircraft. This frictional force helps to slow down the aircraft and bring it to a stop. Therefore, the purpose of aircraft brakes is to retard or reduce the motion of the aircraft by utilizing friction.

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  • 24. 

    The flight control surfaces used to make an aircraft climb or dive are

    • Flaps

    • Spoilers

    • Ailerons

    • Elevators

    Correct Answer
    A. Elevators
    Explanation
    The correct answer is elevators. Elevators are the flight control surfaces that are used to make an aircraft climb or dive. They are located on the horizontal stabilizer at the tail of the aircraft and work by changing the angle of the aircraft's tailplane. When the elevators are deflected upwards, the aircraft's nose pitches up, causing it to climb. Conversely, when the elevators are deflected downwards, the nose pitches down, causing the aircraft to dive.

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  • 25. 

    A barometer is designed to measure pressure is

    • PSI

    • Inches in mercury

    • Relative humidity

    • Ounces of air

    Correct Answer
    A. Inches in mercury
    Explanation
    A barometer is designed to measure pressure, and the unit commonly used to measure pressure is inches in mercury. This unit refers to the height of a column of mercury that is supported by the atmospheric pressure. As the atmospheric pressure changes, the height of the mercury column in the barometer will also change, providing a measure of the pressure. PSI (pounds per square inch) is another unit used to measure pressure, but it is not specifically associated with barometers. Relative humidity and ounces of air are not units used to measure pressure and are therefore incorrect answers.

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  • 26. 

    Variable volume pumps do not require a separate pressure-regulating device in the system because

    • They deliver low pressure

    • They have an integral compensator

    • The case drain will relieve high system pressure

    • There is no angle between the drive shaft and cylinder block

    Correct Answer
    A. They have an integral compensator
    Explanation
    Variable volume pumps do not require a separate pressure-regulating device in the system because they have an integral compensator. This means that the pump itself is able to automatically adjust its output pressure based on the system's demand. The integral compensator allows the pump to maintain a consistent pressure level without the need for an additional regulating device.

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  • 27. 

    The maintenance stand with an adjustable height of 13 to 20 feet is the

    • B-1

    • B-2

    • B-4

    • B-5

    Correct Answer
    A. B-2
    Explanation
    The correct answer is B-2 because it is the only option that falls within the given range of 13 to 20 feet. The other options, B-1, B-4, and B-5, do not have an adjustable height or do not fall within the specified range.

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  • 28. 

    The model 4000 engine trailer can support a maximum load of

    • 7000 lbs

    • 8000 lbs

    • 9000 lbs

    • 10000 lbs

    Correct Answer
    A. 8000 lbs
    Explanation
    The model 4000 engine trailer is designed to handle a maximum load of 8000 lbs. This means that the trailer has been tested and certified to safely carry up to 8000 lbs of weight without causing any damage or compromising its structural integrity. Exceeding this weight limit could potentially lead to accidents or damage to the trailer.

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  • 29. 

    The first practical laminated composite formed was

    • Safety glass

    • Fiberglass

    • Plywood

    • Adobe

    Correct Answer
    A. Plywood
    Explanation
    Plywood was the first practical laminated composite formed because it is made by gluing together thin layers of wood veneer. This process creates a strong and durable material that is resistant to warping and splitting. Plywood is widely used in construction, furniture making, and other applications where strength and stability are important. Safety glass, fiberglass, and adobe are not examples of laminated composites.

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  • 30. 

    The type of flight control system that allows the pilot to control the aircraft if hydraulic pressure is lost is

    • Boost

    • Manual

    • Powered

    • Differential pressure

    Correct Answer
    A. Manual
    Explanation
    The correct answer is manual. In a manual flight control system, the pilot is able to control the aircraft even if hydraulic pressure is lost. This means that the pilot can physically manipulate the controls and directly move the control surfaces of the aircraft, such as the ailerons, elevators, and rudder, without relying on hydraulic assistance. This provides a backup option for the pilot in case of hydraulic system failure, allowing them to maintain control of the aircraft and safely land it.

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  • 31. 

    Another name for a flapper check valve is

    • Ball check valve

    • Gate check valve

    • Cone check valve

    • Restrictor check valve

    Correct Answer
    A. Gate check valve
    Explanation
    A flapper check valve is not commonly referred to as a gate check valve. A gate check valve is a type of check valve that uses a sliding gate or disc to control the flow of fluid. On the other hand, a flapper check valve uses a hinged flapper or disc to allow or prevent the flow of fluid. Therefore, the correct answer is not "gate check valve".

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  • 32. 

    The purpose of the antiskid system is to

    • Reduce friction between the wheel and tire

    • Increase friction between the wheel and tire

    • Prevent wheel skid by applying pressure to the skidding wheel

    • Prevent wheel skid by releasing pressure from the skidding wheel

    Correct Answer
    A. Prevent wheel skid by releasing pressure from the skidding wheel
    Explanation
    The antiskid system is designed to prevent wheel skid by releasing pressure from the skidding wheel. When a wheel begins to skid, it loses traction and can cause the vehicle to lose control. By releasing pressure from the skidding wheel, the antiskid system allows the wheel to regain traction and maintain stability. This helps to prevent accidents and improve overall vehicle safety.

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  • 33. 

    Split wheels are balanced

    • During buildup

    • As an assembly

    • Individually by halves

    • By a self balancing system

    Correct Answer
    A. Individually by halves
    Explanation
    Split wheels are balanced individually by halves. This means that each half of the split wheel is balanced separately to ensure that both halves are equally weighted. This is done to ensure that the wheel rotates smoothly and does not cause any vibrations or imbalance while in use. Balancing the wheels individually by halves allows for more precise balancing and ensures optimal performance and safety.

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  • 34. 

    The boiling point of liquid oxygen (LOX) is

    • -183 degrees C

    • -183 degrees F

    • -297 degrees C

    • -297 degrees F

    Correct Answer
    A. -297 degrees F
    Explanation
    The boiling point of liquid oxygen (LOX) is -297 degrees Fahrenheit. This is a very low temperature, indicating that LOX boils at a very cold temperature.

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  • 35. 

    The major advantage of the manual slide type hydraulic selector valve is its

    • Damping ability

    • Metering ability

    • Capability to all system pressure to build

    • Capability to relieve excess system pressure

    Correct Answer
    A. Metering ability
    Explanation
    The manual slide type hydraulic selector valve has the major advantage of metering ability. This means that it can control the flow rate of hydraulic fluid, allowing for precise and controlled movement of hydraulic actuators. This is important in applications where the speed and precision of movement are crucial, such as in industrial machinery or hydraulic systems used in construction equipment. The metering ability of the valve allows for smooth and controlled operation, enhancing the overall performance and efficiency of the hydraulic system.

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  • 36. 

    The shock strut component that controls the rate of fluid-flow through the orifice is the

    • Check valve

    • Bypass valve

    • Metering valve

    • Flow transmitter

    Correct Answer
    A. Metering valve
    Explanation
    The metering valve is the shock strut component that controls the rate of fluid-flow through the orifice. It regulates the flow of fluid to ensure a smooth and controlled movement of the shock strut, allowing for proper damping and absorption of shocks. The metering valve restricts the flow of fluid, thereby controlling the speed at which the shock strut compresses and extends. This helps maintain stability and control in the suspension system, providing a comfortable and safe ride.

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  • 37. 

    The purpose of the torsion links on a main landing gear is to

    • Reduce oscillation during extension

    • Reduce oscillation during retraction

    • Allow the inner cylinder to rotate with in the outer cylinder

    • Prevent the inner cylinder from rotating with outer cylinder

    Correct Answer
    A. Prevent the inner cylinder from rotating with outer cylinder
    Explanation
    The torsion links on a main landing gear prevent the inner cylinder from rotating with the outer cylinder. This is important because the inner cylinder houses the landing gear strut, which needs to remain in a fixed position during operation. By preventing rotation between the two cylinders, the torsion links ensure that the landing gear functions properly and does not experience any unwanted movement or rotation.

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  • 38. 

    An airtight seal is maintained between split wheel halves by use of

    • A rubber liner

    • An O-ring seal

    • A phenolic ring

    • Machined-mated surfaces

    Correct Answer
    A. An O-ring seal
    Explanation
    The correct answer is an O-ring seal. An O-ring seal is a type of seal that is commonly used to create an airtight seal between two mating surfaces. It is made of a rubber or elastomeric material and is designed to fit tightly into a groove or recess in one of the mating surfaces. When the two surfaces are brought together, the O-ring compresses and forms a tight seal, preventing any air or fluid from escaping. This type of seal is commonly used in split wheel halves to ensure that no air leaks occur between the two halves.

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  • 39. 

    An aircraft's tire's maximum recommended static load is called the

    • Ply rating

    • Serial number

    • Service rating

    • Manufactured wear limit

    Correct Answer
    A. Ply rating
    Explanation
    The ply rating refers to the maximum recommended static load of an aircraft's tire. It indicates the number of layers of fabric or plies used in the tire's construction, which determines its strength and load-carrying capacity. A higher ply rating indicates a tire that can handle a greater static load. Therefore, the ply rating is the correct answer in this context.

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  • 40. 

    The unit capable of providing both AC and DC electrical power in addition to pneumatic power for ground maintenance is the

    • A/M32A-95

    • A/M32A-86

    • A/M32A-60

    • AF/M-32R-3

    Correct Answer
    A. A/M32A-60
    Explanation
    The A/M32A-60 is the correct answer because it is a unit that is capable of providing both AC and DC electrical power, as well as pneumatic power for ground maintenance. The other options, A/M32A-95, A/M32A-86, and AF/M-32R-3, do not have the capability to provide all three types of power.

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  • 41. 

    The main difference between inspection plates and panels is

    • Size

    • Material

    • Location

    • Installation

    Correct Answer
    A. Size
    Explanation
    The main difference between inspection plates and panels is their size. Inspection plates are typically smaller in size and are used to provide access to specific components or areas for inspection or maintenance purposes. On the other hand, panels are larger and are used to cover larger areas or enclosures. They may provide access to multiple components or serve as protective barriers. Therefore, size is the key distinguishing factor between inspection plates and panels.

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  • 42. 

    The reference locations, which are in the vertical direction measured from a reference datum that is usually well below the aircraft, are called

    • Buttlines

    • Waterlines

    • Buttock stations

    • Fuselage stations

    Correct Answer
    A. Waterlines
    Explanation
    Waterlines are reference locations in the vertical direction measured from a reference datum that is usually well below the aircraft. These waterlines are used to determine the position of the aircraft's hull or body in relation to the water surface. They are important for designing and constructing watercraft, ensuring proper buoyancy and stability.

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  • 43. 

    Electrons can be released from their outer orbit by all of the following forces except

    • Heat

    • Cold

    • Chemical action

    • Changing magnetic field

    Correct Answer
    A. Cold
    Explanation
    Electrons can be released from their outer orbit by heat, chemical action, and changing magnetic fields. However, cold temperatures do not have enough energy to overcome the binding forces that hold electrons in their orbits. Therefore, cold is the only force listed that cannot release electrons from their outer orbit.

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  • 44. 

    The size of one micron is four

    • Tenths of an inch

    • Thousandths of an inch

    • Millionths of an inch

    • Billionths of an inch

    Correct Answer
    A. Millionths of an inch
    Explanation
    One micron is a unit of measurement that is equal to one millionth of an inch. This means that if you were to divide an inch into one million equal parts, each part would be one micron in size. Therefore, the correct answer is "millionths of an inch."

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  • 45. 

    The wing components that provide strength and contour shape to the wing are the

    • Ribs

    • Spars

    • Stringers

    • Stiffners

    Correct Answer
    A. Ribs
    Explanation
    Ribs are the wing components that provide strength and contour shape to the wing. They are typically made of lightweight materials such as aluminum or composite materials. Ribs are placed perpendicular to the spars, which are the main load-carrying structures of the wing. Ribs help to distribute the aerodynamic forces evenly across the wing and maintain its shape. They also provide attachment points for other components such as the skin and control surfaces. Overall, ribs play a crucial role in ensuring the structural integrity and aerodynamic performance of the wing.

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  • 46. 

    The effective range of a fully charged handheld fire extinguisher is

    • 5 feet

    • 10 feet

    • 15 feet

    • 20 Feet

    Correct Answer
    A. 20 Feet
    Explanation
    The effective range of a fully charged handheld fire extinguisher is 20 feet. This means that the extinguisher can effectively reach and extinguish fires that are up to 20 feet away from the user. This range is important as it allows the user to maintain a safe distance from the fire while still being able to effectively put it out. Having a longer range ensures that the user can reach fires that may be larger or further away, increasing the chances of successfully extinguishing the fire and preventing further damage.

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  • 47. 

    The force that acts parallel to the relative wind is

    • Lift

    • Drag

    • Gravity

    • Weight

    Correct Answer
    A. Drag
    Explanation
    Drag is the force that acts parallel to the relative wind. When an object moves through a fluid (such as air or water), drag is the resistance force that opposes the motion. It is caused by the friction between the object's surface and the fluid, and it acts in the direction opposite to the object's motion. In the context of aerodynamics, drag is an important force to consider as it affects the performance and efficiency of vehicles, aircraft, and other objects moving through a fluid medium.

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  • 48. 

    Movement about the vertical axis is called

    • Roll

    • Pitch

    • Crab

    • Yaw

    Correct Answer
    A. Yaw
    Explanation
    Movement about the vertical axis is called yaw. Yaw refers to the rotation of an object or vehicle around its vertical axis, causing it to change its direction to the left or right. This movement is commonly seen in aircraft and ships when they change their heading.

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  • 49. 

    Cooler operation in a variable-volume hydraulic pump is provided by

    • Foot valves

    • Oil radiator

    • Creep plates

    • Fluid radiator

    Correct Answer
    A. Creep plates
    Explanation
    Creep plates provide cooler operation in a variable-volume hydraulic pump. Creep plates are designed to create a small gap between the pump's pistons and the cylinder block. This allows a small amount of fluid to continuously flow through the gap, which helps to dissipate heat generated during pump operation. As a result, the pump operates at a lower temperature, reducing the risk of overheating and improving overall efficiency.

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  • Mar 20, 2023
    Quiz Edited by
    ProProfs Editorial Team
  • May 26, 2011
    Quiz Created by
    BHarris019
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